Related Experiment Video
Updated: Aug 16, 2026
Protection of H9c2 Myocardial Cells from Oxidative Stress by Crocetin via PINK1/Parkin Pathway-Mediated Mitophagy
Published on: May 26, 2023
Mechanisms underlying the cardioprotective effect of L-cysteine
D Shackebaei1, N King, B Shukla
1Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Insights
Supplying L-cysteine to rat hearts preserved glutathione levels and improved recovery from ischemia-reperfusion injury. This suggests L-cysteine enhances cardiac antioxidant capacity and energy production, offering potential cardioprotection.
Area of Science:
- Cardiovascular Physiology
- Biochemistry
- Cellular Biology
Background:
- Glutathione (GSH) production is crucial for cellular antioxidant defense.
- L-cysteine availability often limits GSH synthesis in various tissues.
- The role of L-cysteine in cardiac GSH production and protection against ischemia-reperfusion injury requires further investigation.
Purpose of the Study:
- To investigate the hypothesis that L-cysteine supplementation protects the heart against ischemia-reperfusion injury.
- To determine if L-cysteine preserves glutathione levels in the heart during ischemia.
- To assess the impact of L-cysteine on cardiac function and viability post-ischemia.
Main Methods:
- Isolated perfused rat hearts subjected to 45 minutes of global normothermic ischemia.
- Hearts were perfused with or without 0.5 mM L-cysteine added prior to and during ischemia.
- Left ventricular function (rate pressure product) and reperfusion injury (lactate dehydrogenase release) were measured.
- Adenosine triphosphate (ATP) and glutathione (GSH) content were quantified at the end of ischemia.
Main Results:
- L-cysteine treated hearts exhibited significantly higher recovery of rate pressure product compared to controls.
- A significant reduction in lactate dehydrogenase release was observed in L-cysteine treated hearts, indicating less cellular damage.
- Preservation of both ATP and GSH levels during ischemia was significantly better in the L-cysteine supplemented group.
Conclusions:
- Supplementation with 0.5 mM L-cysteine confers significant cardioprotection against ischemia-reperfusion injury in isolated rat hearts.
- The protective mechanisms likely involve enhanced glutathione preservation, leading to improved antioxidant capacity.
- L-cysteine may also contribute to cardioprotection by increasing anaerobic energy production or reducing nucleotide degradation.
Abstract:
In many tissues the availability of L-cysteine is a rate-limiting factor in glutathione production, though this has yet to be fully tested in heart. This study aimed to test the hypothesis that supplying hearts with 0.5 mM L-cysteine would preserve glutathione levels leading to an increased resistance to ischaemia reperfusion. Left ventricular function was measured in isolated perfused rat hearts before, during and after exposure to 45 min global normothermic ischaemia. Control hearts received Krebs throughout, whilst in treated hearts 0.5 mM L-cysteine was added to the perfusate 10 min before ischaemia, and was then present throughout ischaemia and for the first 10 min of reperfusion. Reperfusion injury was assessed from the appearance of lactate dehydrogenase (LDH) in the effluent. In two separate groups of control and treated hearts, ATP and glutathione (GSH) contents were measured at the beginning and end of ischaemia. Hearts treated with 0.5 mM L-cysteine showed a significantly higher recovery of rate pressure product (16,256+/- 1288 mmHg bpm vs. 10,324+/- 2102 mmHg bpm, p < 0.05) and a significantly lower release of LDH (0.54+/- 0.16 IU/g wet weight vs. 1.44+/- 0.31 IU/g wet weight, p < 0.05) compared to controls. Also, the L-cysteine treated group showed significantly better preservation of ATP and GSH during ischaemia in comparison to control. These results suggest that the mechanisms underlying the cardioprotective effects of 0.5 mM L-cysteine may include: increased anaerobic energy production either directly or through reduced degradation of adenine nucleotides; direct scavenging of free radicals; and/or improved antioxidant capacity through glutathione preservation.
Related Concept Videos
01:19Blood Studies for Cardiovascular System II: CRP, Hcy, and Cardiac Natriuretic Peptide Markers
These markers indicate stress or strain on the heart muscle:
Natriuretic Peptides (BNP)
Cardiac myocytes produce these hormones in response to ventricular stretching...
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System